GCSE Physics Revision "Static Electricity (Triple)"

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hi and welcome back to frees science

lessons.

co.uk by the end of this video you

should be able to describe how electrons

can be moved from one insulator to

another if we rub them together you

should then be able to describe how this

can lead to static electricity and to

sparking and remember that all of this

is for triple physics students only I'm

showing you here a manh hold onto a

Vander graph generator you may have seen

one of these at school as you can see

the man's hair is standing on end this

is due to static electricity and we're

going to explore that in this

video so first we're going to take a

look at conductors and

insulators remember that metals are good

conductors of electricity that's because

electrons can easily flow through

Metals objects such as plastic and glass

are insulators they do not conduct

electricity that's because electrons

cannot move through them now a good

example of an insulator is cloth like

everything cloth is covered with

electrons these electrons cannot move

through the cloth because cloth's an

insulator I've now got a piece of

plastic plastic is also an insulator

just like cloth and it's also covered

with

electrons when we rub the plastic with

the cloth electrons move from the

plastic onto the cloth remember that

electrons are negatively

charged so because electrons have moved

onto the cloth the cloth now has an

overall negative charge like

this the plastic has lost electrons so

it now has an overall positive charge

which is equal in size to the charge on

the cloth scientists call this static

electricity you might have experienced

this yourself if you've ever received an

electric shock after walking across a

carpet if we go back to the vandergraph

generator we can see what's happening

I'm showing you here the generator with

the top Dome

removed in the generator we've got a

moving belt as the belt moves electrons

pass from the top plastic roller onto

the

belt now as the belt moves over the

bottom roller electrons pass off the

belt and they're transferred to Earth so

over time the top region of the

generator becomes positively

charged now remember that the generator

normally has a metal Dome like this the

dome acts as a store of positive charge

by allowing it to spread out going back

to our original picture we can see that

the man is holding onto the Dome of the

generator this means that the man now

has an overall positive charge because

the hairs on his head are now positive

they repel each other and they move

apart now under certain conditions

static electricity can cause a spark and

that can be dangerous a good example is

when and an aircraft is

refueled electrostatic charge can build

up as the fuel flows through the

refueling pipe this could cause a spark

and trigger an explosion so to prevent

that both the refueling truck and the

airplane are earthed this prevents any

charges from building up and leading to

a

spark in the next video we're going to

look in more detail at static

electricity and explore the idea of an

electric

field remember you'll find plenty of

questions on I electricity in my vision

workbook and you can get that by

clicking on the link

above okay so hopefully now you should

be able to describe how electrons can be

moved from one insulator to another if

we rub them together you should then be

able to describe how this can lead to

static electricity and to spark

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